Electromagnetic horn



Oct. l, 1940. F; voN volGTLANDER 2,216,380

ELECTRUMAGNETIC HORN 2 Sheets-Sheet l Filed Jan. 14, 1937 Wwf/(VM l FEI Ml w.

Oct. l, 1940. F, voN voxGrLANDER K 2,216,380

ELECTROMAGNETIC HORN Filed Jan. 14, 1937 2 Sheets-Sheet 2 Patented Oct. l, 1940 UNITED STATES PATENT oFFlcE ELEGTROMAGNETIC HORN Application January 14, 1937, Serial No. 120,485

4 claims.

This invention relates to features of electric horn construction and control. Y

This invention has utility when incorporated in horn mounting, adjustment, connections and assembly. These utilities more specically reside in structural adaptations to respond in manufacturing requirements with nicety of control for tone in compact set-up reliable under .the vibra- -tion of motor vehicle use as to resonant means and electrical connections.

Referring to the drawings:

Fig. l is a View of the horn from the side of the motor with the housing or cover removed;

Fig. 2 is a section on the line II-IL Fig. 1, parts of the projector being broken away;

Fig. 3 is a section on the line III-III, Fig. 2, looking at the back of the magnet core from the side toward the diaphragm;

Fig. 4 is a view looking into the armature on the line IV-IV, Fig. 2;

Fig. 5 is a partial section on the line V-V, Fig. 1;

Fig. 6 is a perspective View of a coil clip used with the magnet bracket assembly in Fig. 5;

Fig. 7 is a view of the stem and key sleeve assembly for mounting the armature, on the line VII-VII, Fig. 2;

Fig. 8 is a partial section view showing the armature assembly with the stem on the line VIII-VIII, Fig. 2;

Fig. 9 is a detail view in perspective of contact bracket at the breaker;

Fig. 10 is a wiring diagram of the electrical control connections for this electromagnetic horn;

Fig. 11 is a fragmentary view oi the terminal connections held by spring clip;

Fig. l2 is a perspective view in detail of a terminal plate as used in Fig. 11;

Fig. 13 lis a side elevation of the horn at its mounting; and

Fig. 14 is a detail view of the bracket in the horn mounting on the line XIV-XIV, Fig. l.

Mounting bracket I has plate terminal portion engaged by rivets 2 assembling yieldable Y-lamina 3 in multiple on each side of the plate I. These Y-lamina 3 have arms 4 (Figs. 1, 14) with registering openings 5. Spacer 6 with shoulders l has reduced diameter portions 8 which may be snapped into register with the openings 5 in these Y-arms 4 to assemble this spacer in position to receive bolts 9 in mounting the horn into assembly set-up. These bolts 9 extend through main frame member I0 of the horn to which tubular extension I I is connected to mount straight projector I2 or elbow projector I2 (Fig. 13) flaring to terminate in bead I3.

Oppositely from this projector Il, I2, the Ahorn proper provides cap I4 as major housing, thrust and held into assembly position by a screw I5 so that marginal flange I6 of this cap interfits about the main frame I0 inward from ange Il of the projector portion II. This screw I5 has threaded assembly with U-strap bracket I8, which is snap assembled at openings I9 with the main frame I0.

Adjacent the main frame I0, there is mounted iiexible diaphragm as a partition'between the housing I4 and the projector ll, I2. Extending through this diaphragm 20 is stern 2! having on the projector side of said diaphragm 20, washers 22 to space resonator having at central section 23 with gradual taper dish 24 away from the diaphragm with more abrupt taper 25 back toward the diaphragm, with the resonator rim 26 inthe approximate plane, (preferably within a few hundredths of an inch of coplanar) with the central portion 23 `of lthe resonator. Within the at central portiony 23, washer 2l as lockedby split washer 28 is held by nut 29 on threaded portion 30 of the stem 2l to lock this resonator in spaced assembly relatively to the diaphragm for vibra? tional clearance in horn operation. Against the central portion of the diaphragm 20 about this stem 2l is washer 3l having peripheral flange 32 away from the diaphragm 20. This washer 3| fits against collar enlargement 33 Xed on the stem 2l. This collar enlargement has attened side portions 34 (Figs. 2, 3) to permit ready application of wrench in holding 4the stem for tightening and setting the assembly of the resonator therewith. 1

Adjacent this collar 33 there is tapered clearance 35 of laminae 36 comprising the core for this electromagnet. This laminated magnet core has outer legs 31 and intermediate leg 38 providing grooves or slots 39 therebetween. Additionally, there is central opening 49 throughthis magnet core providing a way for the stem 2I in alignment with its mounting at rthe diaphragmA 29. Thislaminated electromagnet core is fixed relatively to the main frame member I0 by rivets 4I (Figs. l, 3). These rivets 4I mount ears 42 of magnet carrying brackets having upstanding portion 43 against lthe laminae and assembled therewith by rivets 44. L

In these slots 39 is located coil 45 which,v as extending outward from the core, is embraced by clip 46 (Figs. 1, 5, 6) having hook extension 4l which engages with the magnet bracket 43v holding the core in position with the frame l0. This stem 2| as protruding from the opening 40 into the housing |4 has threaded portion 48 (Fig. 2) upon which is mounted sleeve 49 having collapsi-ble flare head 50 with its sections spaced by grooves or slots (Fig. 4). This flare head 50 may seat with laminations 52 of the amature having shrouds or side assembly portions 53 anchored or locking with the laminations 52 assembled by rivets 54. Seating with this armature oppositely from the flare head 50 is washer 55 having away from the armature laminations 52, 53, convex face 56 complemental lto concave seat 51 of washer 58, spaced by leaf spring 59 from washer 60, clamped therewith by nut 6| on threaded portion 62 of this sleeve 49. This means that, upon removal of the housing I4, the nut 6| may be backed off to loosen the rockable bearing 56, 51, in assembling the armature 52 into the desired alignment for determined nicety of air lgap 63 with poles of the elec-tromagnet core. This is permitted due to clearance in practice between the washer 55 and the sleeve 49 of about 1/20 of an inch.

As the nut 6| is loosened to allow the collapsible or clutch portion 59 to release from the stem 2|, attened portions 64 (Fig '1) of the threaded portion 62 ma-y be engaged to rotate this sleeve 49 on the stem 2| either toward or from the diaphragm, and as so rotated into the desired clearance for the air gap 63, the nut 6| may be again brought into the gripping position for holding in such clearance.

This stem 2| has reduced diameter threaded portion 65 (Fig. 2) on which is mounted nut 66 locked by nut 61. This nut 66 reacts as a bumper against insulation plate 68, thereby thrusting exible contact arm 69 with its contact 10 away from opposing contact 1| of rigid arm 12. This is the breaker action response in the device herein. Screws 13 (Figs. 2, l1) through insulation sleeves 14 assemble with bracket15 the spring 59 which yieldably holds the stem 2|. Additionally, there is mounted on these screws`13 spacers 16 and insulation 11 about the insulation sleeves 14, mounting terminal plate 18 spaced by additional insulation 11 from complementa-ry terminal plate 18. Horn control switch 19 (Fig. as closed may cut in energy source as battery 80 and by line 8| (Fig. l) complete circuit to terminal plate 18. The arm 69 has solder connection to line 82 to condenser 83, say of .20 microfarad, thence by line 84 to flange 85 (Figs. 1, 9) of rigid breaker arm 12. This wiring, accordingly, places the condenser 83 in parallel with the contacts 10, 1|. The plate 18 is connected by way of the contacts 1|, 10, to line 86 extending to the coil 45, with circuit completed by way of line 81 therefrom to plate 18', thence by line 88 to the switch 19.

In lieu of plates 18, 18', there may be substituted therefor plates 89 (Figs. 11, 12) adapted to receive bullet-shaped conductor ends 90 of supply lines in eye portions 9| with spring hookover portion 92 adjacent notch 93 adapted to connect the lead therefrom to the coil or condenser.

In the matter of the adjustment of the air gap 63, this it is desirable to eifect accurately. The core may impact the armature. This impact is not destructive as herein disclosed for the laminations of the armature do not tend to cling to the laminations ofthe core. The impact is transmitted to the resonator, and for this transmission it is found in practice in the horn of ,striking of the armature.

general design herein that say with the resonator slightly over three inches diameter, the air gap is desirably held to approximately .027 inch to .030 inch. It hasbeen found that if this dimension under this control is say .032 inch, the tone is subdued and when the air gap is reduced say to .025 inch, the resonator tone is increased but simultaneously there is a harsh mechanical noise therewith. The laminations as disclosed herein deaden the mechanical noise generated by the Furthermore, the armature is of less area laterally than the bounding portions of the field or core which avoids the armature striking rigid shroud portions of the core. The condenser in parallel with the breaker points is a shunt thereabout having value as arc suppressor and also additionally important hereunder; for in this type of horn with the resonator as herein, the contact is of considerably longer interval than with, say electric air or air tone type horn. To obtain the advantage hereunder, it is important there be a sharpness of response, thereby making the note clear. This end is attained by this condenser for building up strength for the current in the set-up herein.

The resonator herein, by its design in cooperation with the air gap and controls, has a frequency of say 2500 cycles per second. Contributing toward this efliciency is the central at region for this resonator disk with the gradual dishing away from the diaphragm into a more abrupt return toward the diaphragm. The dimensions adopted herein, and. found efficient, are the disk rim outer edge to start radially inward at 20 bevel or dish away from the plane parallel to the diaphragm, then a 27 slant to a radius of curvature of .26 inch for a distance of 1.125 inches from the center; lthe disk is 2.87 inches in diameter to the outer portion of the rim taking the 27 slant. There is less steep inward arc approximating a radius of curvature of 3.15 inches to taper inward toward the flat center, of .53 inch to .54 inch diameter. This conguration of the resonator disk makes for tonal efiiciency in promoting the horn operation herein. Shifting of the radial distance inward or outward of the rib or corrugation crest, even slightly, very materially aifects the frequency of this resonator.

What is claimed and it is desired to secure by United States Letters Patent is:

1. An electric signal device embodying a magnet, an armature, and a mounting for the armature including a first washer seated toward the armature and convex away from the armature, a second complementary washer, an externally threaded sleeve having a flare portion seated aga-inst the armature opposite from the washers, anda nut rotatable relatively to the respective washers, said nut on the sleeve clamping the washers against the armature oppositely from the flare means for locking assembly at an adjusted angular position for the sleeve as to the armature in denite parallelism with the magnet.

2. An electric signal device embodying a magnet, an armature, and a mounting for the armature `including a first washer seated toward the armature and convex away from the armature, a second complementary washer, externally threaded means through the washers and armature, there being collapsible flare means seated against the armature oppositely from the washers, and a nut rotatable relatively to the respective washers, said nut being threaded to clamp the Washers against the armature and toward the flare means for collapsing the flare means into locking assembly at an angular adjusted position xing the armature with the flare means in definite parallelism with the magnet. n

3. An electric horn having a projector and a magnet, said horn comprising a diaphragm providing a partition, mounting means for the partition to form a housing isolating the projector from the magnet, an amature for the magnet, a stem fixed with the diaphragm and extending through the magnet into the housing, a sleeve on the stem having a split flare head engaging one side of the armature, complementary elements forming rockable bearing providing means between the armature and stem on the other side of the armature, and locking means engaging the sleeve to clamp the bearing and armature to the sleeve.

4. An electric horn having a projector and a magnet, an armature for the magnet, said horn comprising a diaphragm providing. a partition in the housing isolating the projector from the magnet, a stem Xed with the diaphragm and extending through the magnet into the housing, rocking-bearing-providing means for the armature on the stem relatively to the magnet, saidv means including a sleeve with a flare head and a seat coactive with the head, and longitudinally-effective positioning means on the stem for the armature as to the magnet for varying the spacing between the armature and magnet, there being adjustable means for the rockingbearing-providing means at the armature accessible in the housing independently of through the projector.

FREDERICK VON VO'IGTLAN DER. 

